Circuit breaker panelboard



June 29,1965 N. K ENYERES ETAL 3,192,447

CIRCUIT BREAKER PANELBOARD 4 Sheets-Sheet 1 Fig. I

INVE NTORS And W ATTORNEY WITNESSES NICI'IOIO'S Kenyeres Roberi G. A W [7/ IZ June 1965 N. KENYERES ETAL 3, 92,

CIRCUIT BREAKER PANELBOARD 4 Sheets-Sheet 2' Filed July 29, 1960 June 29, 1965 N. KENYERES 'ETAL 3,192,447

CIRCUIT BREAKER PANELBOARD Filed July 29, 1960 4 Sheets-Sheet 3 Fig. 7

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$111629, 1965 N. KENYERES ETAL CIRCUIT BREAKER PANELBOARD Filed July 29, 1960 4 Sheets-Sheet 4 6 an co Fig.9

Fig. IO

United States Patent C) 3,192,447 CIRCUIT BREAKER PANELBOARD Nicholas Kenyeres, Vilasar de Mar, Spain, and Robert G.

Anderson, Streetsville, Ontario, Canada, assignors to Canadian Westinghouse Company, Limited, Hamilton, Ontario, Canada I Filed July 29, 1966, SenNo. 46,218 8 Claims. (Cl. 317-119) This invention relates, generally, to panelboards, and more particularly, to panelboards for'housing a plurality of circuit interrupter units.

Panelboards of the type under consideration generally include a pan or base which is resiliently mounted on the back wall of a housing and which has mounted thereon a plurality of circuit interrupters. The base, circuit interrupters and a grounded shield member which is disposed over the outside of the circuit interrupters, are all biased toward the outside of the enclosure by the resilient mounting means. Four spacing members or spacers are disposed front panelboard with improved means for grounding the shield member of the panelboard.

Since the trim portion of a panelboard is generally mounted after the housingis in place, it is necessary to have some sort of a device which will pull the trim in towards the panelboard housing in order to mount the trim to the housing. This was accomplished in the past by the use of an adjusting member that was rotated to position a lever so that when a bolt was rotated, the lever, which rode up or down the bolt depending upon the direction of rotation of the bolt, would be in a position to either fasten or unfasten the trim. This necessitated two operations, i.e., firstrotating the adjusting member to position then rotating the bolt.

A further object of this invention is to provide improved means for fastening the trim to a panelboard housing.

Another object is to provide an improved trim clamp which can .be adjusted by merely operating one screw member.

For certain applications in the past, circuit interrupters were mounted in panelboards by being bolted down at their line ends to conductors, and being attached at their load ends by means of hooks which engaged in notches in the breaker housings. The interrupters or breakers-Were mounted in two rows in an end-to-end relationship with the load ends of adjacent breakers of opposite rows being physicially and electrically connected and bolted to a single rigid conductingmember that was connected to a main bus bar. In order to remove one of the breakers, it was necessary to remove the rigid conducting member and thus disconnect both the breaker to be removed and also the adjacent breaker. This was true because the load end of the interrupter was hooked and could not be tilted up to allow the breaker to be pulled away from under a part ofthe rigid conducting member.

Accordingly, another object of the invention is to provide a panelboard with improved mounting means that permits removal of the circuit interrupters singularly without necessitating disturbance of any other circuit interrupter.

Another object of the invention is to provide a panelboard with improved mounting means including a spring clip having a shelf part for supporting one end of a circuit interrupter, and a resilient V-shaped part which will Patented June 29, 1965 deflect upon engagement thereof with the one end of the interrupter to thereby permit a mounting or dismounting of the circuit interrupter with a generally pivotal motion about the other end of the interrupter.

Another obejct of the invention is to provide a panelboard with improved mounting means in accordance with the preceding object which mounting'means is shaped from one piece of material.

Other objects of the invention will be explained fully hereinafter or will be apparent to those skilled in the art.

In accordance with the invention, a pan or base is resiliently mounted on the back wall of a panelboard housing by means of tour bolts that are threaded into four studs that are attached to the housing back wall, and by means of four insulating spacing members each of which is tubular and fits over one of the mounting bolts and one of the studs. The spacing members space the base member from a metallic shield which covers all but the operating handle portions of a plurality of circuit interrupters that are mounted on the base. The resilient means biases the base, the circuit interrupters and the shield member in an outward direction toward the front of the panelboard to thereby compensate for any misalignment of the panelboard housing with the wall in which the panelboard is mounted. The insulating spacers are provided with notches near their outer ends and are shaped in such a manner that they will rock in a direction to engage the shield member within the notches. At least one of the spacing members will have an opening extending to the inside thereof so that when the member is rocked into position, a tongue portion of the metallic shield member will pass through the opening to engage the grounded metallic bolt, which is positioned within the tubular spacing member, to thereby ground the shield member. The spacing members and the base are provided with novel means for locking the base to prevent outward movement thereof relative to the spacing members. The base is provided with four openings that receive the four spacing members. The openings and the spacing membersare shaped in such a way that after the base is in position, the spacing members can be rotated into positions in which they lock the base in place.

A one-piece spring clip is provided having a shelf part for supporting one end of a circuit interrupter and a generally resilient V-shaped part, that readily deflects upon engagement thereof with the one end of the interrupter to ermit a mounting or dismounting of the interrupter with a generally pivotal motion about its other end.

A novel trim clamp is provided comprising a lever structure that is supported within a bracket by means of a screw that is threaded into a tapped opening in the lever structure. Means are provided to limit rotation of the lever structure so that upon rotation of the screw the lever structure will ride up or down the screw to either fasten or unfasten the panelboard trim.

For a better understanding of the nature and objects of the invention, reference may be had to the following detailed description, in conjunction with the accompanying drawings, in which:

FIGURE 1 is a view taken along line I- I of FIGURE 2 with the circuit interrupters of FIGURE 2 being left out of FIGURE 1 for the purposes of clarity;

FIGURE 2 is a view taken along line -IIII of FIG- URE 1 including the circuit interrupters that are mounted within the panelboard and including the upper portion of the panelboard housing;

FIGURE 3 is an elevational View, on an enlarged scale, of one of the spamrs mounted on the base;

FIGURE 4 is a top view of the spacer shown in FIG- URE 3;

FIGURE 5 is a sectional view taken along line VV of FIGURE 3;

FIGURE 6 is an elcvational view, on an enlarged scale and partly in section, illustrating one of the spring clips of the invention;

FIGURE 7 is a view, on an enlarged scale, of a portion of the pan-elboard illustrating the trim clamp which is shown in the unfastened position;

FIGURE 8 is a top view of the trim clamp shown in FIGURE 7;

FIGURE 9 is a plan view of the base member of the invention;

FIGURE 10 is a plan view of the shield member of the invention; and

FIGURE 11 is a View taken along line XI-XI of FIGURE 5.

Referring to the drawings and particularly to FIGURES 1 and 2, the panelboard 9 shown therein comprises a mounting pan or base. It) and a plurality of center insulating supports 11 supporting a plurality of bus bars 12A, 12B and 12C to which are connected a plurality of circuit interrupting units that are indicated genera ity at 13 in FIGURE 2.

As shown in FIGURE 2, the base III) is resiliently mounted on four stud members 15 (only two of which are shown) which are welded or otherwise attached tothe back wall 17 of a panel board housing 13 that in"- cludes the back wall 17 and four side walls 19. A spring 21 fits over each of the stud members 15 to resiliently bias the base It) in an outward direction. A metallic shield member 23 is disposed near the outer side of thehousing 13 and is spaced from the base It? by means.

of four insulating spacing members or spacers indicatedv generally at 25.

The spacers 2 5 are of a generally tubular construction;

and each fits over a stud member 153 and a metallic bolt:

27 (FIGURE 5) which is screwed into the stud member 5377 and therefore the bolts 27, which are attached to the:

stud members, are also grounded. The spacers 255 maintain a constant predetermined distance between the base 10 and the shield member 23 so that the biasing spring 21 which forces the base member outward, also forces. the shield member 23 toward the outer part of the hous ing 18 which movement is restricted by L-shaped flanges: 29 (FIGURE 2) that are attached to a trim member 31. The trim member 31 is attached to the housing, 18 in a manner to be hereinafter specifically described.

A plurality of generally U-shaped conducting mem-- bers 33 are mechanically and electrically connected to the bus bars 12A, 12B and 12C, by means of nuts 34 and bolts 35 (FIGURE 2). Going from top to bottom in FIGURE 1, the first and fourth U-shaped members 33 are attached to legs or" the bus .bar the second and fifth members 33 are attached to the bus bar 123 and the third and sixth members 33 are attached to the bus bar 12C. The way in which the bus bars are mounted within the panelboard is described in more detail in the copending application of Nicholas Kenyeres and Robert G. Anderson, Ser. No. 790,269, new Patent Number 3,054,934, filed January 30, 1959 and assigned to the assignee of the instant application. Two rows of circuit interrupters 13 (FIG. 2) are mounted within the housing 16 in an end-to-end relationship with the line ends of adjacent breakers of the opposite rows being connected to a common U-shaped member 33:. The line end of. each of the circuit interrupters 13 is mechanically attached to one of the U-shaped members 33 by means of a bolt that passes through a flange portion 37 of the member 33 and threadedly engages a terminal structure (not shown) of the interrupter. The other or load end of each interrupter 13 is supported on a raised shelf portion 38 which is a formed over part of a supporting member indicated generally at 39, which supporting memall.

her has a formed over base portion as that is welded or iotherwise secured to the panelboard base It). The load EE-d of each interrupter 13 is held in place by means of Each of the spacing members is a generally elongated member molded of insulating material and having :an opening 55 (FIG. 5) extending therethroug-h. A

groove 5'7 is provided at one side of each of the members extending most of the length of the member. Each spacing member 25 is shaped in such a manner that a cross-section thereof through the part which includes the groove 57 (as shown for example in FIG. 1), shows a generally semi-circular portion that blends into a generally U-shaped portion. A cross-section taken for instance along the line XI-XI (FIG. 11), shows a generally semi-circular portion that blends into a generally :1- tangular portion. The opening 55 of each spacer 25 forms an internal shoulder 59 upon which the head of the bolt 27 rests when the parts are in position. A notch 61 is provided near the outer end of each of the spacers 25, which notch leads into an opening 63 that provides a passage into the internal opening of the tubular shaped spacer.

During assembly, each of the bolts 27 is passed through the opening 55 of one of the spacing members 25 and "screwed into the tapped opening of one of the stud mem- Zbers 15. As can be seen in'FIGURE 5, the opening 55 is wider at the bottom to receive one of the stud members 15. This wider part extends higher than the member 15 in order to allow adjustment of the panelboard which adjustment will be hereinafter specifically described. The four spacing members 25 are then rotated so that the semicircular portion of each of them faces toward the inside of the housing 155, i.e. rotated from the positions in which they appear in FIGURE 1. This puts the semicircular portion of each of the spacers 25 in position to mate with one of four semi-circular openings 67 (FIG. 9) in the base 10. The base is then passed down over the four spacing members 25 to engage the springs 21 that are positioned over the four studs 15. The base 11 is forced against the bias of the springs 21 until a projection 71 (FIGS. 3 and 5), which is molded integral with the spacing member 25, is higher than the plane of the base 10, so that the member 25 can be rotated relative to the base 10. Each of the members 25 is then rotated until the projection or key portion 71 is aligned with a slot or key receiving opening 69 (FIG. 9) in one of the openings 67 of the base It), at which time the base 10, under the bias of the springs 21, will be forced outward until it engages with the rectangular portion (FIG. 11) of each of the spacers 25. In this position, engagement of the projection 71, of each of the spacers 25 in one of the slots 69, locks the spacers 25 against further rotation. The openings 55 in the members 25 are large enough compared to the bolts 27 and stud members 15 to permit a rocking motion of the members 25 relative to the members 27 and 15. The base It engages the rectangular portion (FIG. 11) of each of the spacers 25 and, as seen in FIG. 1, the semi-circular portion of each of the members 25 is now positioned in one of the openings 67. The upward force of the base 10, therefore rocks each of the members 25 in'a direction to secure, as will be hereinafter described, the shield 23 (FIG. 2) witihn the notches 61 (FIG. 5) of the members 25.

With the base 10 and insulating members 25 in place, and with the circuit interrupters 13 properly mounted on the base, the shield member 23 is placed in position.

As is illustrated in FIGURE 10, four openings 75 in the shield 23 receive the four spacers 25. The shield 23 shown in FIGURE 10 has twelve openings 77 therein for receiving the operating handles of twelve circuit interrupters 13 two of which are shown in FIGURE 2. As is well-known in the art, the number of openings 77 in the shield 23 will depend upon the number of circuit interrupters that are to be supported in the panelboard. The spacing members 25 are rocked back to their normal ver tical positions, and the shield is placed in position, over these members. The shield 23 rests on a ledge 78 (FIG. of each of the four spacing members 25. When the shield is in position, each of the spacing members 25 will rock back to its locking position, in which position the notch 61 (FIG. 5) in each of the spacers receives an edge 78 (FIG. adjacent one of the openings 75 to lock the shield in position.

When the parts are in position, the height and/ or slant of the shield 23, base 10 and the parts that are supported therebetween, can be adjusted merely by turning the bolts 27 by means of a screwdriver or other suitable tool. When the parts are in place, the bolts 27 are screwed into their associated stud members 15. The spacing member 25 and theparts associated therewith i.e. the base 19, shield 23 and parts supported therebetween, are all biased outward by the springs 21. This outward movement is restricted by engagement of the internal ledges 59 (FIG. 5) of the spacing members 25 with the heads 3t] of their associated bolts 27. As each of the bolts 27 is screwed into and out of its associated stud member 15, its height within the enclosure 16- and therefore the height within the enclosure of its associated spacer 25, base 10, shield 23 and the parts supported between the base and shield, are varied by the amount of rotation of the bolts 27. It

can be understood that this type of adjustment can be Very easily made.

The metallic stud members (FIG. 2) and metallic bolts 27 (FIG. 1) are grounded, being connected to the metallic housing 18 which is grounded in a well-known manner. This invention includes novel means for grounding the shield members 23 to provide a dead-front panelboard. Two tongue portions 80 (FIG. 10) are provided along the edges 78 of the two upper openings 75 of the shield 23. These tongue portions are positioned such that each will extend into one of the passages 63 (FIG. 5) of the associated insulating spacers to engage the metallic bolt that is disposed within the spacer member 25 to thereby ground the shield member 23. It is to be understood that the shield member 23 could be grounded by having only one tongue portion 80 engage only one of the bolts 27, but for increased reliability, tongue portions 80 can be provided at two (FIG. 10) or more of the openings 75 to engage two or more of the bolts 27.

Improved means are provided for mounting the trim member 31 to the panelboard housing 18. As can be seen in FIGURE 2, a flange portion 79 extends out from each of the side walls 19 of the housing 18. The trim member 31 is attached to the flange 79 of the housing 18 by means of a plurality of trim clamps 81 only two of which are seen in FIGURE 2. As is best illustrated in FIGURE 7, each of the trim clamps 81 includes a generally U-shaped bracket member 83, a screw 85 and a lever structure indicated generally at 87. The trim clamp 81 is attached to the trim 31 by means of the bolt 85 which passes through an opening in the trim and through openings in the legs of the U-shaped brackets 83. The screw 85 is locked in position by means of a friction ring 89 that snaps into a notch 91 in the screw 85 to prevent outward movement of the screw. The friction ring 89 frictionally loads the screw to prevent excessive freedom of rotation of the screw 85. A slot 93 is provided in the head of the screw 85 so that the trim clamp may be worked by a screwdriver. The lever structure 87 includes a tapped member 95 that is secured within an opening in a lever member 97. When the screw 85 is rotated in a clockwise (FIG. 8) direction, it carries the lever structure 87 with it until a stop portion 99 (FIG. 8) engages the bracket 83 at 101 to limit the clockwise movement of the lever structure 87, whereupon further rotation of the screw causes the lever structure 87 to ride up the screw until the lever member 97 engages the flange 79 of the housing 18 to pull the trim member 31 toward the housing. When it is desired to release the trim member 31 from the housing 18, the screw 85 is rotated in a counterclockwise (FIG. 8) direction carrying with it the lever structure 87 until the lever 97 engages the bracket 83 at 103, whereupon further rotation of the screw 85 will cause the lever structure 87 to ride down the screw to release the lever 97 from under the flange .79 of the sidewall 19. Although only one of the lever structures 81 is herein specifically described, it is to be understood that a plurality of lever structures are used in order to mount the trim 31 to the housing 18.

Improved means are provided for mounting the circuit interrupting units 13 (FIG. 2) within the housing 18 of the panelboard 9. As is best illustrated in FIGS. 1, 6 and 9, the two elongated metallic supporting members 39 are welded or otherwise secured, at their base portions 40, to the panelboard base 10 on opposite sides of the panelboard base. The load end of each of the six circuit interrupters that is supported by each of the supporting members 39, rests on two of the raised shelf portions 38 straddling on opening between the shelf portions. The openings between the shelf portions are formed when the resilient V-shaped spring clips 41 are stamped from each of the one-piece supporting members 39. There is a re silient V-shaped spring clip 41 for each of the circuit interrupters.

Refer-ring to FIGURE 2, a circuit interrupter 13 is dismounted by loosening the screw 36 at the line end of the interrupter and tilting the interrupter upward in a pivotal direction about the line end, which motion is permitted by deflection of the spring clip 41, to thereby free the load end of the interrupter from the spring clip 41, whereupon the interrupter is pulled out from under the flange 37 of the generally U-shaped member 33. The interrupter 13 is mounted into the panelboard by first sliding the line end thereof under the flange 37 of the generally U-shaped member 3-3 and then pivoting the interrupter down into position, during which movement the bottom of the load end of the interrupter 13 engages the V-shaped spring clip 41 causing the spring clip to deflect until it snaps into the slot 42 of the interrupter 13 when the interrupter reaches the mounted position shown in FIGURE 2. It can be be understood that the generally U-shaped member 33 need not be detached from the panelboard during the mounting operation of only one of the circuit interrupters 13 which operation does not disturb the other interrupters 13 that is connected to the same U-shaped member 3-3.

From the foregoing description, it can be understood that applicants have provided an improved panelboard embodying improved means for supporting the parts within the housing in a spaced relationship. Improved means are provided for grounding the shield member to provide a dead-front structure. A novel trim clamp is provided which is operated by merely rotating one screw member. A novel one-piece spring clip is provided having a raised shelf portionfor supporting one end of a circuit interrupter, and a resilient V-shaped spring clip that readily deflects upon engagement thereof with the one end of the interrupter thereby permitting a mounting or dismounting of the interrupter with a generally pivotal motion about its other end. With the use of this spring clip, circuit interrupters may be mounted or dismounted singularly within the panelboard without necessitating disturbance of any other circuit interrupter.

Since numerous changes may be made in the abovedescribed construction and different embodiments of the invention may be made without departing from the spirit and scope thereof, it is intended that all of the matter contained in the foregoing description or shown in the accomares-it? 3! r ibanying drawings shall be interpreted as illustrative and h t "'11 it limiting sense.

We claim as our invention; V

, 1. A pane board comprisihg, in combination, a housing havinga east"; wall and side Walls, a base disposed in alinity to the back wall, a shield disposed in a plane generally parallel to the plane of the base, an insulating spacing member disposed between the base and shield, the spacing member having a notch near one end, and means rocking the spacing member in a direct-ion to engage a part of the shield within said notchi v 2. In a panelboard, in combination, a housing having a back Wall and side Walls, a base disposed near said Wall, a shield disposed in a plane generally parallel to the plane of said base, a plurality of spacing members disposed be ween said base and said shield, each of said spacin 1; members having a notch near one end thereof, resilient means biasing said base away from said back wall, and

' each of said spacing members being constructed such that said biasing of said resilient means causes the spacing member to rock in a direction to engage a part of said shield within the associated notch.

3. A panelboard comprising, in combination, a housing having a back wall and side walls, a base disposed wvithin said housing in proximity to said back wall, an

insulating spacing member having an inner part engaging said base, a notch near the outer part of said spacing member, a shield having an edge defining an opening therein, a part of said spacing member extending through said opening, resilient means biasing said base away from said back wall, the inner part of said spacing member being shaped such that the biasing of said resilient means causes said spacing member to tilt into a position where said notch receives said edge whereby said spacing member spaces said shield from said base.

4. A panelboard comprising, in combination, a housing having a back wall and side walls, a base supported within said housing and having an opening therein, a shield supported Within said housing and having an opening therein, a supporting member supported by said back wall and on tending through said opening in said base and shield, an insulating spacing member having an opening therein for receiving said supporting member, said opening being large enough to permit a rocking motion of said spacing member relative to said supporting member, the inner part of said spacing member engaging said base, the outer part of said spacing member having a notch therein, means biasing said base away from said back wall to thereby cause said spacing member to rock in a direction to engage part of said shield within said notch.

5. A panelboard including, in combination, a housing having a back wall and side walls, supporting means including an insulating spacing member, a base and a shield supported by said supporting means in a spaced relationship within said housing, means biasing said base toward said shield, said spacing member being rotatable about its longitudinal axis to a locked position, and means preventing rotation of said spacing member Q t its longitudinal axis when said spacing member is in a certain predetermined position relative to said base.

6. A panelboa'rd comprising, in combination, a housing having a back Wall and side Walls, supporting means including an insulating spacing member, a base and a shield supported by said supporting means in a spaced relationship within said housing, said spacing member having a notch near one eiid resilient ineaiis biasing said base away fioirl said back wall causing said notch to engageably re ceive part or said shield, said spacing member being r05 tata'ble about "is longitudinal axis to a locked pdsitiori, means pi. e; ig rotation of said spacingmember when said spacing member is iri the locked position; i p

7. A panelboard including, in combination, a housing having a back wall and side walls; supporting means including an elongated insulating spacing member; a base and a shield supported by said supporting means within said housing; said base and shield being maintained in a spaced relationship by means of said spacing member; resilient means biasing said base, shield and spacing mean 'ber outward away from said back wall of said housing; means limiting said outward movement of said base, shield and spacing member, said base having a slot therein; said spacing member having a key portion; said spacingmern her being rotatable about its longitudinal axis to a locked position; and said key portion in the locked position engaging in said slot in said base to prevent axial rotation of said spacing member.

3. A panelboard eo'mp'risii'zg, in combination, a holising having a back wall and side walls, a base disposed in proximity to said back wall, a metallic shield disposed in a plane generally parallel to the plane of said base, supporting means including an insulating elongated spac ing member having an opening extending through its length and an electrically'grounded metallic bolt positioned within said opening, said spacing member spacing said siheld from said base, said spacing member having a notch near one end which notch leads into a passage that provides access to the internal opening of said tubular spacing member, means tilting said spacing member in a direction to place said notch in a position wherein a part of said metallic shield passes through said notch to thereby engage said part of said metallic shield with said grounded bolt.

References Qited by the Examiner UNITED STATES PATENTS 1,633,097 6/27 Hart 317-114 1,826,817 10/31 Olley et a1 292-256.73 2,036,044 3/36 Hammer 317-419 2,138,408 11/38 Rowe 317119 2,314,225 3/43 Leece 317-99 2,837,699 6/58 Fore 3171 19 2,946,928 7/60 Slade 317-119 3,054,934 9/62 Kenyeres et a1. 317-119 3,061,761 10/62 Blair: 3l7101 JOHN F. BURNS, Primary Examiner. SAMUEL BERNSTEIN, Examiner. 

1. A PANELBOARD COMPRISING, IN COMBINATION, A HOUSING HAVING A BACK WALL AND SIDE WALLS, A BASE DISPOSED IN PROXIMITY TO THE BACK WALL, A SHIELD DISPOSED IN A PLANE GENERALLY PARALLEL TO THE PLANE OF THE BASE, AN INSULATING SPACING MEMBER DISPOSED BETWEEN THE BASE AND SHIELD, THE SPACING MEMBER HAVING A NOTCH NEAR ONE END, AND MEANS ROCKING THE SPACING MEMBER IN A DIRECTION TO ENGAGE A PART OF THE SHIELD WITHIN SAID NOTCH. 